i need to unlock my macbook, i changed the password but shows lock; to unlock waits 24 hrs?

Are you referring to this screen?

If so, it is asking you to enter the firmware password.

If you don't remember this password, you will need to schedule an in-person visit to your local Apple Store or Apple Authorized Services Provider to get this resolved. You will also need to bring a copy of either your original sales receipt or invoice for "proof of purchase." If you have neither of these, then there isn't much Apple (or any of us here) can do to assist you with this.

Is this what your situation is?

https://discussions.apple.com/thread/1292165